THE Pakistani Taliban has threatened to attack foreign aid workers trying to help the eight million people who are still affected by flooding.

Hundreds of aid workers have arrived in the country to help people in need of clean water, food and medicine.

But many of the worst-affected areas are in the north-west of the country, where militants have kidnapped and murdered with impunity. American officials claim to have discovered that the insurgents plan to attack aid convoys.

One official said: "According to information available to the US government, Tehreek-e-Taliban plans to conduct attacks against foreigners participating in the ongoing flood-relief operations in Pakistan.

"It may also be making plans to attack federal and provincial ministers in Islamabad."

The warning has prompted the United Nations (UN) to review security measures for its workers. The World Health Organisation (WHO) said the threat had already affected its plans for distributing aid.

A Western diplomat in Islamabad said: "There are hundreds of foreign workers and it's only a matter of time before something very bad happens."

Ahmed Farah Shadoulx, a WHO spokesman, said: "With this threat, it means either we have to downsize the operation -- which means less access to those affected by the floods -- or we have to take more mitigation measures to reduce the security risk. That means more resources."

Weeks of flooding have affected an estimated 17.2 million people. Hundreds of thousands are still cut off from help by impassable roads and bridges -- a month after the crisis began.

Local authorities ordered nearly half-a-million people to evacuate towns in the southern Sindh province yesterday as rising water threatened flood defences.

The government also ordered the immediate evacuation of up to 600,000 people from towns and villages along southern reaches of the Indus River as unprecedented floods swept towards the sea.

The security warning is the first suggestion that relief efforts may be targeted by militants, although the Pakistani Taliban had urged the country to reject aid from "infidels".

Targeted

"We condemn American and other foreign aid and believe that it will lead to subjugation," said a spokesman for the militant group.

Earlier this month in Afghanistan, insurgents killed a British doctor, Karen Woo, and six other aid workers.

Meanwhile, representatives from the Pakistani government and the International Monetary Fund are considering "all options", according to a spokesman for the IMF.

Pakistan's finance minister, Abdul Hafeez Shaikh, yesterday joined the talks that started earlier this week in Washington aimed at reviewing the impact of the floods on the country's budget and economy.

So far, 1,542 people have been killed and about 17.2 million people have lost their homes and livelihoods, according to the UN Office for the Co-ordination of Humanitarian Affairs.

Donors have given 60pc of the $460m (€360m) needed to fund the emergency response, said the IMF.